Method of preparing lightweight window anti-static circuit and optional heating circuit

Abstract

A method of producing a transparent plastic window containing embedded therein a novel static electricity dissipating circuit (hereinafter referred to as an anti-static circuit), which may also contain a heating circuit insulated therefrom.

We claim: 
     
       1. A method of making a composite transparency comprising applying a pattern of wire to an opposite pair of major surfaces of a first layer of rigid transparent plastic selected from the class consisting of acrylic plastic and polycarbonates, one of said patterns comprising relatively widely spaced runs of continuous wire and the other of said patterns comprising relatively closely spaced runs of continuous wire, press polishing said layer of rigid transparent plastic at sufficient heat and pressure to smooth the opposite major surfaces thereof so that the wire is embedded just below each of the opposite major surfaces, attaching suitable terminal means to the wire embedded adjacent each of the opposite surfaces, and fusing a second layer of rigid transparent plastic selected from the class consisting of acrylic plastic and polycarbonates at elevated pressure and temperature against the first layer of plastic having the wires embedded therein to form a composite transparency having wire with widely spaced runs embedded adjacent a major surface thereof and wire with closely spaced runs embedded within the thickness in relatively spaced relation from the opposite major surfaces of side composite transparency. 
     
     
       2. A method as in claim 1, further including laminating a layer of plastic interlayer material taken from the class consisting of polyurethanes and plasticized polyvinyl acetals to the major surface of said composite transparency that is spaced from both of said wire runs. 
     
     
       3. The method as in claim 2, comprising laminating a rigid transparent layer taken from the class consisting of glass, polycarbonate plastic, and acrylic plastic to the opposite surface of said layer of interlayer material laminated to said composite transparency. 
     
     
       4. A method as in claim 1, comprising applying a first pair of strips of electroconductive material to said surface to which said closely spaced runs of wire are applied, applying said closely spaced runs so that the end portions of at least several of said runs extend beyond said first layers of electroconductive material, applying a second strip of electroconductive material in superimposed relation over each of said first strips with said end portions disposed between said first and second strips of electroconductive material in strip form prior to said press polishing. 
     
     
       5. A method as in claim 1, comprising applying elongated wire mesh to the surface containing the relatively widely spaced runs of wire in contacting relation to an end portion of at least several of said runs prior to said press polishing step. 
     
     
       6. A method as in claim 1, further comprising applying a first pair of strips of electroconductive material to said surface to which said closely spaced runs of wire are applied, applying said closely spaced runs so that the end portions of at least several of said runs extend beyond said first strips of electroconductive material, applying a second strip of electroconductive material in superimposed relation over each of said first strips with said wire end portions disposed between said first and second strips of electroconductive material prior to said press polishing, applying elongated wire mesh to the surface containing the relatively widely spaced runs of wire prior to said press polishing step, attaching terminal means to said composite strips of electroconductive material that is bonded to said relatively closely spaced runs of said one wire, and connecting additional terminal means to the elongated wire mesh in electroconductive contact with said relatively widely spaced runs of said wire. 
     
     
       7. A method of making a composite transparency comprising applying a pattern of widely spaced wire runs to a major surface of a first layer of rigid transparent acrylic plastic, applying a pattern of closely spaced wire runs to a major surface of a second layer of rigid transparent plastic selected from the class consisting of acrylic plastic and polycarbonates, attaching suitable terminal means to end portions of at least several of each of said runs, press polishing said first and second layers to embed said wire runs within and just below said respective major surfaces, assembling said layers with said major surface of said first layer facing away from said second layer and said major surface of said second layer facing said first layer, and fusing said second layer while so assembled against the first layer of plastic having the wires embedded therein to form a composite transparency having wire with widely spaced runs embedded adjacent a major surface thereof and wire with closely spaced runs embedded within the thickness in relatively spaced relation from the opposite major surfaces of said composite transparency. 
     
     
       8. A method as in claim 7, further including laminating a layer of plastic interlayer material taken from the class consisting of polyurethanes and plasticized polyvinyl acetals to the major surface of said composite transparency that is spaced from both of said wire runs. 
     
     
       9. The method as in claim 8, comprising laminating a rigid transparent layer taken from the class consisting of glass, polycarbonate plastic, and acrylic plastic to the opposite surface of said layer of interlayer material from that laminated to said composite transparency. 
     
     
       10. A method as in claim 7, comprising applying a first pair of strips of electroconductive material to said surface to which said closely spaced runs of wire are applied, applying said closely spaced runs so that the end portions of at least several of said runs extend beyond said first layers of electroconductive material, applying a second strip of electroconductive material in superimposed relation over each of said first strips with said end portions disposed between said first and second strips of electroconductive material in strip form prior to said press polishing. 
     
     
       11. A method as in claim 7, comprising applying elongated wire mesh to the surface containing the relatively widely spaced runs of wire in contacting relation to an end portion of at least several of said runs prior to said press polishing step. 
     
     
       12. A method as in claim 7, further comprising applying a first pair of strips of electroconductive material to said surface to which said closely spaced runs of wire are applied, applying said closely spaced runs so that the end portions of at least several of said runs extend beyond said first strips of electroconductive material, applying a second strip of electroconductive material in superimposed relation over each of said first strips with said wire end portions disposed between said first and second strips of electroconductive material prior to said press polishing, applying elongated wire mesh to the surface containing the relatively widely spaced runs of wire prior to said press polishing step, attaching terminal means to said composite strips of electroconductive material that is bonded to said relatively closely spaced runs of said one wire, and connecting additional terminal means to the elongated wire mesh in electroconductive contact with said relatively widely spaced runs of said wire. 
     
     
       13. A method of making a composite transparency comprising applying a pattern of wire to an opposite pair of major surface of a first layer of rigid transparent plastic selected from the class consisting of acrylic plastic and polycarbonates, one of said patterns comprising relatively widely spaced runs of continuous wire and the other of said patterns comprising relatively closely spaced runs of continuous wire, attaching suitable terminal means to the wire adjacent each of the opposite major surfaces, assembling a second layer of rigid transparent plastic selected from the class consisting of acrylic plastic and polycarbonates against the surface of said first layer to which said closely spaced runs are applied, and press polishing said assembly at elevated pressure and temperature to fuse said second layer to the first layer of plastic and to embed the wires therein to form a composite transparency having wire with widely spaced runs embedded adjacent and just below a major outer surface of said transparency and wire with closely spaced runs embedded within the thickness in relatively spaced relation from the opposite, press polished major surfaces of said composite transparency.